EP0343870A1 - Dispositif de blocage des pièces - Google Patents

Dispositif de blocage des pièces Download PDF

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Publication number
EP0343870A1
EP0343870A1 EP89305090A EP89305090A EP0343870A1 EP 0343870 A1 EP0343870 A1 EP 0343870A1 EP 89305090 A EP89305090 A EP 89305090A EP 89305090 A EP89305090 A EP 89305090A EP 0343870 A1 EP0343870 A1 EP 0343870A1
Authority
EP
European Patent Office
Prior art keywords
clamp arm
workpiece
clamping device
workpiece clamping
holding position
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP89305090A
Other languages
German (de)
English (en)
Other versions
EP0343870B1 (fr
Inventor
Norman James Campbell
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to AT89305090T priority Critical patent/ATE83189T1/de
Publication of EP0343870A1 publication Critical patent/EP0343870A1/fr
Application granted granted Critical
Publication of EP0343870B1 publication Critical patent/EP0343870B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27B—SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR
    • B27B29/00—Gripping, clamping, or holding devices for the trunk or log in saw mills or sawing machines; Travelling trunk or log carriages
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27B—SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR
    • B27B17/00—Chain saws; Equipment therefor
    • B27B17/0041—Saw benches or saw bucks

Definitions

  • the present invention relates generally to a workpiece clamping device, and particularly to a device suitable for holding any form of workpiece in a fixed location to enable working operations to be performed on it.
  • a major application of the invention relates to the holding of rough felled timber although the invention may find application to other forms of workpiece.
  • the present invention seeks to provide a method and apparatus for holding workpieces, especially timber workpieces, offering improvements in a relation to means previously employed for holding workpieces, in particular in dealing with the technical problem of quickly engaging or releasing a workpiece to allow a plurality of operations requiring the workpiece to be held in different positions to be performed successively.
  • the invention is formed as a trestle or saw-horse suitable for holding rough felled timber to enable it to be cut into pieces using a chainsaw or other such saw.
  • the apparatus comprises a folding trestle having pivotally interconnected frames adapted to provide, in their working position, an upwardly open V-shape structure into which timber and the like can be lowered for support in a conventional way, and the invention provides means by which such timber can be securely held on the support for working operations to be performed on it.
  • the invention is formed as a workpiece clamping device entirely separate from a support, which may be fitted to a support or to other pieces of apparatus in circumstances where workpiece clamping may be required.
  • a workpiece clamping device of the present invention may be fitted to the end of a ladder to enable the ladder to be securely attached to a branch of a tree so that access to the tree can be gained readily and securely.
  • the present invention seeks, therefore, among other objectives, to provide a workpiece clamping device which can obviate the necessity for a second operator when using a chainsaw, by providing means by which a workpiece such as a log to be sawn can be held securely in a fixed position allowing the chainsaw operator to work on it whilst nevertheless using both hands for the chainsaw whilst cutting.
  • the present invention finds applications in a wider range than merely as a log saw bench, however, and in general can be characterised as a workpiece clamping device having means by which a workpiece can be readily secured thereto or released therefrom without using screw threaded clamps or vices.
  • a workpiece clamping device comprises support means defining a reaction surface, a clamp arm pivotally mounted on the support means and shaped to engage a workpiece between itself and the reaction surface of the support means when in a workpiece holding position, and resilient biasing means for urging the clamp arm towards the workpiece holding position, when the clamp arm is located between the holding position and a neutral position, and away from the holding position towards a release position when the clamp arm is located on the side of the neutral position remote from the holding position.
  • the clamp arm is further provided with trigger means actuable by the workpiece itself or otherwise for causing the clamp arm to move from the release position past the neutral position towards the holding position.
  • the clamp arm is preferably curved in a plane perpendicular to the pivot axis about which the clamp arm is turnable. This has the beneficial effect that the operating end of the clamp arm can act on the workpiece with a reaction force which is inclined, towards the pivot axis, from that which would be applied by a straight pivoted clamp arm, thereby obviating any tendency of the clamp to exert a component of force away from the pivot which might tend to cause displacement of the workpiece by the ramp effect.
  • the clamp arm is pivoted to the support at a point intermediate its ends to define a jaw end of the clamp arm on one side of the pivot and a tail end of the clamp arm on the opposite side of the pivot.
  • the jaw end of the clamp arm may be provided with teeth for engaging a rough sawn log, or with a frictional pad such as a rubber or plastics block for frictionally engaging the workpiece.
  • the tail end of the clamp arm may be shaped such that it projects from the general plane of the said reaction surface of the support means to which the clamp arm is pivoted when the clamp arm is in the said release position.
  • the tail of the clamp arm may itself form the said trigger means by causing rotation of the clamp arm away from the release position towards the holding position when contacted by a workpiece causing displacement of the tail portion when positioned against the reaction surface.
  • the said resilient biasing means may be achieved in any one of a number of ways.
  • the resilient biasing means comprises a tension spring secured at one end to the support means and attached at the other to a flexible connection member joined in turn to the said clamp arm.
  • the said flexible connection member may be a rope or, and preferably, a chain or any other linear flexible, preferably substantially inextensible member.
  • the said chain is preferably attached to the said clamp arm by a rigid connector link having a plurality of teeth facing corresponding teeth of the clamp arm when the latter is in the said holding position.
  • the flexible connection member may pass over a guide device which determines the position of the said rigid connector link when the clamp arm is in the said holding position such that the said jaw end of the clamp arm and the said rigid connector link are counterposed when the clamp arm is in the said holding position.
  • the connector link and the clamp arm thus face one another and experience relative approaching movement by approach of the clamp arm to the holding position thus closing together on the workpiece to retain it in position. Any tendency of the workpiece to rotate between the clamp arm and the reaction surface causes the connector link to grip more firmly and in so doing increase the spring tension to counteract the incipient rotation.
  • the support means preferably include upwardly divergent members defining a V-shape volume for receiving a workpiece, the said reaction surface facing inwardly of the said volume and the clamp arm being positioned to urge a workpiece in the said V-shape volume towards the narrow end thereof.
  • This embodiment may be constructed as a saw-horse or log bench traditionally having two cruciform frame members defining the V-shape volume within which a log to be sawn is readily held.
  • the said upwardly divergent members of such an embodiment are preferably the upper limbs of respective leg frames pivotally connected together to form such a trestle or saw-horse.
  • reaction surface is constituted by a generally planar support table having an opening through which a said clamp arm projects.
  • the present invention may also be comprehended as apparatus for holding a workpiece comprising a support having ,upwardly diverging members defining a generally V-shape volume for receiving a workpiece, and a resiliently biased workpiece clamp having a clamp arm pivotally mounted to the support for engaging a workpiece thereon to urge it into the said V-shape volume.
  • the first embodiment of the present invention formed as a saw-horse or trestle, is generally indicated by the reference numeral 11 and constituted by two flat pivoted frames 12, 13 interconnected along a pivot axis X-X.
  • the frame 12 comprises two generally rectangular leg frames 14, 15 joined at their lower ends by a horizontal rail 16.
  • Each of the leg frames 14, 15 is composed of respective parallel legs 14a, 14b and 15a, 15b joined at their upper ends by horizontal struts 14c, 15c.
  • the main frame 13 is, likewise, composed of two inverted U-shape leg frames 17, 18, each composed of two parallel legs 17a, 17b and 18a, 18b joined by a bight limb or strut 17c, 18c and the lower ends of the inverted U-shape leg frames 17, 18 are joined by a horizontal rail 19.
  • the two leg frames 14, 15 are also joined together, in the region of the pivot axis X-X, by two upper horizontal rails 20, 21 the first of which is secured, such as by welding, to the underside of the leg frames 14, 15 and the other of which is secured, at a position slightly displaced along the length of the frames 14, 15 to the other side thereof.
  • the leg 17b is pivotally to the leg 14b and the leg 18b is pivotally connected to the leg 15b so that the two frames 12, 13 turn about the axis X-X from the erected position shown in Figure 1 to the collapsed position shown in Figure 2, in which position the inverted U-shape sub frames 17, 18 of the side frame 13 lie within the outlines of the inverted U-shape sub frames 14, 15.
  • the sub frames 17, 18 come into contact with the upper transverse struts 20, 21 to define the limit of turning movement
  • the sub frames 17, 18 contact the lower struts 16 and the sub frames 14, 15 contact the transverse strut 19.
  • the two inverted U-shape sub frames 14, 17 and the two inverted U-shape sub frames 15, 18 form respective pairs of cruciform legs the upper limbs of which, that is the part of each sub frame above the pivot line X-X form upwardly open diverging volumes for receiving a workpiece such as the log indicated in broken outline and identified by the reference numeral 25.
  • the apparatus is provided with two workpiece holding clamps which are identical to one another and therefore only one of which will be described hereinbelow, namely that attached to the inverted U-shape leg frame 17.
  • the leg 17b has, near its upper end, a boss 26 from which projects a pivot pin on which is pivoted a lug 27 welded to an arcuately curved clamp arm 28 which is separated into two portions by the lug 27, namely a tail portion 29 on one side of the lug and a jaw portion 30 on the end remote from the tail portion 29.
  • the jaw portion 30 of the clamp arm 28 is provided with a serrated plate 31 forming a plurality of teeth.
  • the arcuate clamp arm 28 is also provided with a second lug 32 to which is pivoted a rigid connector link 33 by a pivot which extends to the opposite side of the clamp arm 28 from that to which the pivot pin passing through the lug 27 extends.
  • the rigid connector link 33 is itself provided with a set of serrations 34 facing the serrations of the plate 31 to form a counterposed jaw.
  • the rigid link 33 is also connected to one end of a chain 35 which is guided between the two upper transverse struts 20, 21 and is jointed at its lower end to the upper end 36 of a tension spring 37 the other end of which is joined to a tensioner 38 connected to the lower transverse rail 19.
  • Tension in the spring 37 thus draws the chain 35 through the space between the two transverse struts 20, 21 pulling the rigid connector link 33 downwards and thus urging the clamp arm 28 to turn in a clockwise sense as viewed in Figures 1 and 2 to bring the serrated plate 31 into contact with two abutment stops 39, 40 which are welded to the upper transverse strut 20.
  • the arcuate clamp arm 28 is provided with a handle loop 41 by which it can be turned manually about the pivot 26 and the two upper transverse struts 20, 21 are provided with a platform member 42 conveniently of wood or plastics.
  • the apparatus of the present invention can be made entirely of metal, apart from the platform member 42 for strength and durability although some components may be replaced with plastics should this be found desirable.
  • the tail portion 29 of the clamp arm 28 projects into the V-shape volume defined by the upper limbs of the legs constituting the cruciform frame member.
  • the dimensions of these components are so chosen that when a log 25 is placed between the upper limbs of the cruciform leg frames it depresses this to a point where the boss 32 is moved back past the pivot 27 so that the spring 37 then urges the clamp arm 28 in a clockwise direction to bring the serrated jaw 31 into contact with the log 25 to hold it securely in position.
  • the tension applied by the spring 37 also urges the rigid link 33 towards the log 25, in an attempt to straighten the chain 35 thereby reinforcing the holding effect.
  • Working operations, such as sawing on the log 25, can then be performed single handedly without risk of movement of the log 25 during these operations.
  • the clamping device illustrated in Figure 3 is generally indicated with the reference numeral 46 and comprises a rectangular frame 47 having a first boss 48 constituting a pivotal connection for an arcuately curved clamp arm 49 having a tail portion 50 and a jaw portion 51 which, as in the embodiment of Figures 1 and 2, is provided with a serrated jaw plate 52 and a loop handle 53.
  • FIG. 5 illustrates the clamping device in its set or cocked position ready to receive a workpiece
  • Figure 6 illustrates the clamping device after having been triggered when it is drawn to a holding position by the spring.
  • Figures 7 and 8 illustrate the holding device of Figures 3 to 4 fitted to a ladder 63, and differs from the embodiment of Figures 3 and 4 only in the provision of two pulleys 64, 65 and a release line 66 connected to the handle loop 53 to allow the release and cocking of the jaw.
  • the clamp arm is biased to clamp onto, for example, a branch, from above. It is also possible to mount the clamp inverted, however, so that the clamp arm acts from below. This simplifies the release mechanism since the arm can be directly connected to the release line 66 without the need for the pulleys 64, 65.
  • Figures 9 and 10 show an embodiment in which the clamping members are fitted to the underside of a workbench having a substantially flat working surface 67 with two slots 68, 69 through which the clamp arms 28 can project.
  • the supporting framework is constituted by the cruciform structure of the embodiment of Figure 1, whilst in the embodiment of Figure 10 an alternative folding structure is illustrated.
  • the closure of the jaws upon triggering by displacement of the tail portion 29 of the clamp arm 28 takes place immediately the relative positions of the pivot 26 and the boss 27 are such that the spring 37 can apply the appropriate turning moment to the clamp arm 28.
  • this motion is delayed or slowed by the introduction of a damper, for example in the path of the chain 35, so that closing motion of the jaw 31 of the clamp arm 28 does not take place too rapidly.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Wood Science & Technology (AREA)
  • Forests & Forestry (AREA)
  • Jigs For Machine Tools (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
  • Clamps And Clips (AREA)
  • Gripping Jigs, Holding Jigs, And Positioning Jigs (AREA)
  • Eye Examination Apparatus (AREA)
  • Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
  • Holo Graphy (AREA)
EP89305090A 1988-05-26 1989-05-19 Dispositif de blocage des pièces Expired - Lifetime EP0343870B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT89305090T ATE83189T1 (de) 1988-05-26 1989-05-19 Werkstueck-klemmeinrichtung.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB888812549A GB8812549D0 (en) 1988-05-26 1988-05-26 Log holding trestle
GB8812549 1988-05-26

Publications (2)

Publication Number Publication Date
EP0343870A1 true EP0343870A1 (fr) 1989-11-29
EP0343870B1 EP0343870B1 (fr) 1992-12-09

Family

ID=10637615

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89305090A Expired - Lifetime EP0343870B1 (fr) 1988-05-26 1989-05-19 Dispositif de blocage des pièces

Country Status (6)

Country Link
US (1) US5072918A (fr)
EP (1) EP0343870B1 (fr)
AT (1) ATE83189T1 (fr)
CA (1) CA1326865C (fr)
DE (1) DE68903786T2 (fr)
GB (2) GB8812549D0 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2746009A1 (fr) * 2012-12-24 2014-06-25 Norwood Industries, Inc. Plaque à cliquet de pivotement

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE517581C2 (sv) * 1998-04-15 2002-06-25 Nils Tallving Anordning vid vedkapning
CA2420758C (fr) * 2002-03-04 2007-10-30 Honda Canada, Inc. Dispositif de transport
US20060103090A1 (en) * 2004-05-21 2006-05-18 Fernandes Eric X Industrial cart
US20090065996A1 (en) * 2007-09-10 2009-03-12 Anthony Coca Device for cutting firewood
CN105860577B (zh) * 2010-06-03 2018-03-16 M技术株式会社 铜酞菁微粒的制造方法
US9004477B2 (en) * 2011-04-27 2015-04-14 Chad M. Neumann Saw buck
CN108908499B (zh) * 2018-06-21 2020-12-08 江苏融威实业有限公司 一种应用于木料切割的快速夹持定位装置

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2499450A1 (fr) * 1981-02-10 1982-08-13 Hannan Robert Chevalet de sciage
GB2095167A (en) * 1981-03-25 1982-09-29 Geest Ind Group Ltd Saw bench

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2709615A (en) * 1952-11-17 1955-05-31 Jr William C Barnes Door stop
FR1132347A (fr) * 1954-04-30 1957-03-07 Appareil servant aux menuisiers pour maintenir les portes et fenêtres dans la position horizontale
US3034546A (en) * 1961-03-23 1962-05-15 Raymond A Parsons Collapsible sawbuck
NL8303017A (nl) * 1983-08-30 1985-03-18 Christianus Martinus Adrianus Werkwijze voor het zagen van hout en zaagbok.
US4718652A (en) * 1986-05-30 1988-01-12 Liebenstein Lowell G Sawbuck
FR2612116B1 (fr) * 1987-03-09 1989-06-30 Plouvier Henri Chevalet

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2499450A1 (fr) * 1981-02-10 1982-08-13 Hannan Robert Chevalet de sciage
GB2095167A (en) * 1981-03-25 1982-09-29 Geest Ind Group Ltd Saw bench

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2746009A1 (fr) * 2012-12-24 2014-06-25 Norwood Industries, Inc. Plaque à cliquet de pivotement
US9676116B2 (en) 2012-12-24 2017-06-13 Norwood Industries Inc. Pivot ratcheting log dog

Also Published As

Publication number Publication date
DE68903786T2 (de) 1993-05-13
GB2218936B (en) 1991-12-11
GB2218936A (en) 1989-11-29
US5072918A (en) 1991-12-17
CA1326865C (fr) 1994-02-08
DE68903786D1 (de) 1993-01-21
GB8812549D0 (en) 1988-06-29
EP0343870B1 (fr) 1992-12-09
ATE83189T1 (de) 1992-12-15
GB8911750D0 (en) 1989-07-05

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